New results on the halo structure of 8B

Research output: Contribution to journalArticle


The longitudinal momentum distribution of Be fragments after fragmentation of B and the one-proton removal cross section (σ-1p) in a carbon target were measured at 1440 MeV/u with the fragment separator FRS used as an energy-loss spectrometer. The results show a narrow momentum distribution with a FWHM value of 91 ± 5 MeV/c and a large cross-section, σ-1p = 98 ± 6 mb. Both these results support the interpretation of a spatially extended proton orbit forming a halo in the B ground state. The momentum distribution and the one-proton removal cross section are shown to be reproduced with a three-body wave function for 8B where the target is treated as a black disc in the breakup process.


  • M H Smedberg
  • T Baumann
  • T Aumann
  • L. Axelsson
  • U. C. Bergmann
  • M J G Borge
  • D. Cortina-Gil
  • L. M. Fraile
  • H Geissel
  • L. Grigorenko
  • M. Ivanov
  • N. Iwasa
  • R. Janik
  • B. Jonson
  • H Lenske
  • G. Münzenberg
  • T. Nilsson
  • A Richter
  • K. Riisager
  • C. Scheidenberger
  • G Schrieder
  • W Schwab
  • H. Simon
  • B. Sitar
  • P. Strmen
  • K. Sümmerer
  • M. Winkler
  • M V Zhukov
External organisations
  • Chalmers University of Technology
  • GSI Helmholtz Centre for Heavy Ion Research
  • Aarhus University
  • CSIC Instituto de Estructura de la Materia (IEM)
  • Comenius University
  • RIKEN Nishina Center for Accelerator-Based Science
  • Justus Liebig University Giessen
  • CERN
  • Technical University of Darmstadt
Research areas and keywords


  • Breakup reactions, Momentum distributions, Nuclear structure, One-proton removal cross section, Unstable nuclei
Original languageEnglish
Pages (from-to)1-7
Number of pages7
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Issue number1-2
Publication statusPublished - 1999
Publication categoryResearch
Externally publishedYes